1-Phenyl-3H-1,4-benzodiazepine-2,5-(1H,4H)-diones

ABSTRACT

Compounds of the formula   wherein R1 is phenyl, fluoro-phenyl, chloro-phenyl, bromo-phenyl, trifluoromethyl-phenyl or nitro-phenyl, and R2 is fluorine, chlorine, bromine, trifluoromethyl, nitro, amino, cyano or hydroxyl; THE COMPOUNDS ARE USEFUL AS PSYCHOSEDATIVES AND ANTICONVULSIVES.

United States Patent 1191 Bauer et al.

[451 Oct. 21, 1975 l-PHENYL-3H-l,4-BENZODIAZEPINE-2,5-

(II-1,411 )-DIONES [75] Inventors: Adolf Bauer, lngelheim am Rhein;

Karl-Heinz Weber, Gau-Algesheim; Peter Danneberg, Ockenheim; Franz-Josef Kuhn, Bingen, Rhine, Germany [73] Assignee: Boehringer Ingelheim GmbH,

Ingelheim am Rhein, Germany 221 Filed: Nov. 8, 1973 21 Appl. No.: 413,795

Related US. Application Data [63] Continuation-impart of Ser. No. 316,266, Dec. 18,

1962, abandoned.

OTHER PUBLICATIONS Iacobelli et al., .1 Het. Chem." Vol. 2, pp. 323-325, (1965).

Primary Examiner-Norma S. Milestone Assistant Examiner-Robert T. Bond Attorney, Agent, or FirmHammond & Littell [57] ABSTRACT Compounds of the formula wherein R is phenyl,

bromo-phenyl, nitro-phenyl, and R is fluorine, chlorine, bromine, trifluoromethyl,

nitro, amino, cyano or hydroxyl; the compounds are useful as psychosedatives and anticonvulsives.

fluoro-phenyl, chloro-phenyl, trifluoromethyl-phenyl or 5 Claims, No Drawings l-PHENYL-3H-l ,4-BENZ()DlAZEPlNE-2.5 (IH,4H)-DIONES This is a continuation-inpart of copending application Ser. No. 316,266 filed Dec. 18, 1972 now abandoned. V

This invention relates to novel l-phenyl-3H-l.4- benzodiazepine-2,5-(lH,4H)v-diones, as well as to methods of preparing these compounds.

More particularly, the present invention relates to a novel class of compounds represented bythe formula H ll 1 C-N CH (1) R x z 2 l f o wherein R is phenyl, fluoro-phenyl, chloro-phenyl, bromophenyl, trifluoromethyl-phenyl or nitro-phenyl, and

R is fluorine, chlorine, bromine, trifluoromethyl, hi-

R is hydroxyl, O-tosyl, lower alkanoyloxy, halogen or preferably lower alkoxy,

to a ring closure reaction at room temperature or moderatley elevated temperatures in a conventional inert solvent medium, such as a'lower alkanol, ethyl acetate, tetrahydrofuran or dimethylacetamide, and optionally in the presence of a condensation agent, such as sodium methylate, sodium bicarbonate or triethylamine.

The ring closure reaction may be applied either to an isolated compound of the formula 11 or to a reaction mixture containing a compound of the formula ll which results from the reaction pursuant to the equation where R. R, and R have the meanings previously defined and X represents a nucleophobic group which may readily be exchanged for the NH -group, such as chlorine, bromine, iodine, O-tosyl or lower al kanoyloxy. To form such a reaction mixture. a compound of thc formula 111 is either introduced into liquid ammonia. or a solution of a compound of the formula III in an inert solvent medium, such as tetrahydrofuran. dioxane, dimethylformamide or methanol, is reacted with a compound which releases ammonia in solution, such as an ammonium salt or hexamethylenetctramine.

In those instances where it is desired to prepare an end product ofthe formula I wherein R, is o-substituted phenyl, it is preferred to perform the ring closure reaction in a closed autoclave where it proceeds to completion within a very short time at room temperature.

The starting compounds embraced by formula III are new, but they may be obtained by methods involving known chemical principles. For instance. a compound of the formula [11 wherein R is methoxy and X is chlorine may be obtained by the following reaction sequence:

where R, and R have the meanings'previously defined. More particularly, this reaction is carried out by dissolving the o-phenylamino-benzoic acidlV in an inert organic solvent, such as benzene, toluene, xylene or dimethylformamide, refluxing the solution with chloroacetic acid anhydride, dissolving compound lla thus obtained in a dilute lower alkanol, and adding a small excess of diazomethane to the solution to form compound llb which is then reacted, as described above,

with liquid ammonia or an ammonia-releasing compound to yield a compound of the formula II. Method B By oxidizing a benzodiazepinone of the formula H CN CH; (V) R 2 wherein R and R have the same meanings as in formula l, with a strong oxidizing agent, such as potassium permanganate, activated manganese dioxide or a mixture of chromic acid and sulfuric acid.

The oxidation with potassium permanganate or chromic acid/sulfuric acid is most advantageously performed in a water-miscible solvent medium which is itself not oxidized under the oxidation reaction conditions, such as acetone, methyl ethyl ketone, glacial acetic acid, dioxane, tetrahydrofuran or mixtures of any two or more of these.

The oxidation with activated manganese dioxide may also be performed in the presence of a substantially waterimmiscible organic solvent medium, such as ethyl acetate, diethyl ether, methylene chloride or chloroform.

In either case the optimum oxidation reaction temperature depends upon the particular starting compound of the formula V and may vary, in general, between 20,C and the boiling point of the particular solvent medium which is employed.

A starting compound of the formula V may be obtained by subjecting a lower alkyl o-amino-benzoate of the formula wherein R, and R have the same meanings as in formula I, to a ring closure reaction as described in German patent application No. P 21 65 310, filed in West Germany on Dec. 29, i971.

The following examples further illustrate the present invention and will enable others skilled in the art to understand it more completely. It should be understood, however, that the invention is not limited solely to the particular examples given below.

EXAMPLE 1 8-Nitro-l-phenyl-3H-l ,4-benzodiazepine-2,5( lH,4H dione by method A a. 26 gm of 4-nitro-N-phenyl-anthranilic acid were dissolved in 500 ml of absolute benzene, 26 gm of chloroacetic acid anhydride were added to the solution, and the resulting mixture was refluxed for 1 hour. Thereafter, the reaction mixture was extracted several times with water, and the organic phase was dried over magnesium sulfate and then vacuum-filtered. The filtrate was evaporated in vacuo, and the residue was recrystallized from isopropyl ether/cyclohexane; yielding '30 gm (9871 of theory) of N-chloroacctyl-Nphcnyl-4-nitroanthranilic acid, m.p.l72i73C. I i

b. 10 gm of N-chloroacetyl-N-phenyl 4-nitroanthranilic acid were dissolved in a mixture consisting of 1 liter of methanol and ml of water and. while stirring the solution, a slight excess of diazomethane dissolved in ether was added over aperiod of ten minutes. Thereafter. the reaction solution was evaporated to dryness in vacuo, and the residue was. recrystallized from methanol, yielding 10 gm (97% of theory) of methyl N-chloroacetyl-N-phenyl-4-Nitroanthranilate, m.p. 126-l27C. I

c. 9. gm of N-chloroacetyl-N-phenyl-4-nitroanthranilic acid were dissolved in ml of acetone, the solution was admixed with 8 gm of potassium iodide, and the resulting mixture wasstirred for 20 hours at room temperature. Thereafter, the reaction solution was evaporated in vacuo, the residue was admixed with water, the aqueous mixture was extracted with ethyl acetate, and the organic phase was dried with magnesium sulfate and then evaporated in vacuo. Theresid ua'l oil was dissolved in 20 ml of methanol, the resulting solution was admixed with 200 ml of liquid ammonia, and the mixture was allowed to stand for 1 hour and was then poured over ice. The aqueous mixture was now neutralized with glacial acetic acid and subsequently extracted several times with ethyl acetate. The combined organic extracts were admixed with activated charcoal, dried and vacuum-filtered, the filtrate "was evaporated in vacuo, and the residue was recrystallized from acetonitrile, yielding 4.9 gm (64% of theory) of the compound of the formula which had a melting point of 222223C.

EXAMPLE'Z 8-Trifluoromethyl-l-phenyl-3H-l,4 benzodiazepine- 2,5-(1H, 4H)-dione by method A N-phenylanthranilic acid analogous to Example 1(a)] were dissolved in 250 ml of dimethylacetamide, the solution was admixed with 40 gm of methyl iodideand 30 gm of potassium acetate, and the resulting mixture was stirred for 30minutes at room temperature. Thereafter, the reaction mixture was diluted with 1 liter of water and was then extracted several times with methylene chloride. The combined extracts were dried and evaporated in vacuo, the oily residue was taken up in asmall amount of acetonitrile, insoluble crystalline'impurities were filtered off, the filtrate was evaporated .in vacuo, the residue was dissolved in 300 ml of acetone, 10 gm of sodium iodide were added to the solution, and the resulting mixture was stirred for 20 hours at room temperature. Thereafter, the acetone was evaporated in ous mixture was extracted with ethyl acetate, and the organic extract solution was dried with magnesium. sulfate and then evaporated again in vacuo. The residual oil was dissolved in 30 ml of methanol, the solution was admixed with'250 ml of liquid ammonia, and the mixture was allowed to stand for one hour at room temperature. Thereafter, the reaction mixture was poured over ice, the aqueous mixture was neutralized with glacial acetic acid and then extracted with ethyl acetate, the organic extract solution was admixed with activated chatcoalfand the mixture was dried and vacuumfiltered. The filtrate was evaporated in vacuo. and the residue was recrystallized from methylene chloride/isopropyl ether, yielding 9.3 gm (41% of theory) of the compound of the formula F C .l

which had a melting point of 249 25lC.

EXAMPLE 3 S-Chlorol -phenyl-3H-l ,4-benzodiazepine-2,5-

(lH,4H)-dione by method B 2.5 gm of 8-chloro-1-phenyl-3,4-d ihydro-(2H,5 H)-l, 4-benzo diazepin-5-one were dissolved in 250 ml of acetone, and the solution was admixed at room temperature with 5 ml of an oxidizing solution which had been prepared by dissolving 2.7 gm of chromium-Vl-oxide in 2.3 ml of concentrated sulfuric acid and diluting the solution to ml with distilled watercThe reaction mixture was stirred for one hour at room temperature and was then vacuum-filtered through diatomaceous earth. The filter cake was washed with acetone. the filtrate was evaporated in vacuo, and the residue was recrystallized from acetonitrile, yie lding'2.4 gm (88% of theory) of the compound of the formula which had a melting point of 244-245c.

EXAMPLE 4 Using a procedure analogous to that described in Example 1, 8-bromo-l-phenyl-3H-l,4-benzodiazepine- 2,5-( 1H, 4H)-dione, m.p. 261262C of the formula was prepared from N-chloroacetyl-N-phenyl-4-bromoanthranilic acid.

EXAMPLE 5 Using a procedure analogous to that described in Example 1 8-bromol -(p-bromo-phenyl )-3H-l ,4- benzodiazepine-2,5-(1H,4H)-dione, m.p. 28028lC. of the formula 0 H II I /CH N--C was prepared from N-chloroacetyl-N-(p-bromophenyl)-4-bromoanthranilic acid.

EXAMPLE 6 Using a procedure analogous to that described in Example l, 8-hydroxy-l-phenyl-3H-l,4-benzodiazepine- 2,5-(1H, 4H)-dione, m.p. l-l7lC, of the formula- 0 H ll l CN\ CH2 T" CQHS \O was prepared from N-chloroacetyl-N-phenyl-4- hydroxy-entranilic acid.

EXAMPLE 7 Using a procedure analogous to that described in Example 8cyano-l-phenyl-3H-l,4-benzodiazepine- 2,5-(lH, 4H)-dione, m.p. l55l57C (decomp), of the formula 0 H t l Q f NC N C d i o.

was prepared from N-chloroacetyl-N-phenyl-4-cyanoanthranilic acid.

EXAMPLE 8 Using a procedure analogous to that described in Example l, 8-amino-l-phenyl-3H-l,4-benzodiazepine- 2,5-(1H, 4H)-dione, m.p. 285287C, of the formula was prepared from N-chloroacetyl-N-pheny|-4-aminoanthranilic acid.

EXAMPLE 9 Using a procedure analogous to that described in Example l, 8-chloro-l-(o-chloro-phenyl)-3H-l,4- benzodiazepine-2,5-( l H,4H)-dione, m.p. 249250C, of the formula O H l was prepared from N-chloroacetyl-N-(o-cholorophenyl)-4-chloro-anthranilic acid.

EXAMPLE 10 Using a procedure analogous to thatdescribed in Example 8-chl0rol-(o-bromo-phenyl )-3H-l ,4- benzodiazepine -2,5-( lH,4H)-dione, m.p. 254255C,

of the formula was prepared from N-chloroacetyl-N-(o-bromophenyl)-4-chloroanthranilic acid.

EXAMPLE 11 Using a procedure analogous to that described in Example l, 8-chlorol -o-fluoro-pheny|)-3H-l ,4- benzodiazepine -2,5-(lH,4H)-dione, m.p. 215 2l6C. of the formula was prepared from phenyl)-4-ch|oro-antrhanilic acid.

EXAMPLE l2 Using a procedure analogous to that described in Eit- I l. 8-trifluoromethyl-l-( o-chloro-phenyl)-3H- ample I l.4-benzodiazcpine-2.5-( 1H.4H )-dione. v 256257C. of the formula was prepared from N-chloroa'cetyl-N-(o-chloro phenyl)-4-trifluoromethyl-anthranilic acid.

EXAMPLE l3 Using a procedure analogous to that described in Ex;- ample l, benzodiazepine -2,5-(1H,4H)-dione, m.p. 24l-242C, of the formula I was prepared from N-chloroacetyl-N-(o-chlorophenyl)-4-n'itro-anthranilic acid.

EXAMPLE 14 Using a procedure analogous to that described in Example 8-trifluoromethyl-l(o-fluoro-phenyl)-3H-l .4-

of the formula .phenyl)-4-trifluoromethyl-anthranilic acid.

N-chloroacctyl-N o-fluoro- EXAMPLE Using a procedure analogous to that described in Example l, R-chloro1-(o-trifluoromethyl-phenyl)-3H- 1,4-benzodiazepine-2,5-( l H,4H )-dione, m.p. 265267C, of the formula was prepared from N-chloroacetyl-N-(ortrifluoromethyl-phenyl) -4-chloro-anthranilic acid.

The compounds of the present invention,= that is those embraced by formula 1 above, have useful phar macodynamic properties. More particularly, they exhibit psychosedative (tranquilizing) and anticonvulsive activities in warm-blooded animals, such as mice, rats, dogs and minks.

Particularly effective are those compounds of the formula 1 wherein R is phenyl or halo-phenyl and R is chlorine or trifluoromethyl.

While both the psychosedative and the anticonvulsive activities are concurrently present in all of the compounds embraced by formula I, one or the other of these activities may be more pronounced in the individual species. For example, 8-chloro-l-phenyl-3H-l ,4- benzodiazepine-2,5-(1H,4H)-dione has a more pronounced tranquilizing activity, while the anticonvulsive effect is more pronounced in 1-pheny1-8- trifluoromethy1-3H-l,4-benzodiazepine-2,5-(1H,4H)- dione.

The toxicity of the compounds of the instant invention is extremely low; the LD of all of the compounds embraced by formula I is in excess of 2,000 mgm/kg p.o. (mouse). in fact, the LD of most of the compounds could not be exactly determined because it was physically impossible to administer to the animals the large amount required to ascertain the median lethal dose by conventional methods.

For pharmaceutical purposes the compounds according to the present invention are administered to warmblooded animals perorally or parenterally as active ingredients in customary dosage unit compositions, that is, compositions in dosage unit form consisting essentially of an inert pharmaceutical carrier and one effective dosage unit of the active ingredient, such as tablets, coated pills, capsules, wafers, powders, solutions, suspensions, emulsions, syrups, suppositories and the like. One effective psychosedative and anticonvulsive dosage unit of the compounds according to the present invention is from 0.0083 to 0.84 mgm/kg body weight, preferably 0.083 to 0.42 mgm/kg body weight. The pre ferred daily dose rate is from 0.166 to 2.5 mgm/kg body weight.

The following examples illustrate a few dosage unit compositions comprising a compound of the present invention as an active ingredient and represent the best mode contemplated of putting the invention into prac- The pill core composition is compounded from the following ingredients:

2.5-( 1H,4H l-tlionc 5.0 parts Lactose 28.5 Corn starch 15.0 Gclatin 1.0 Magnesium stcarutc 0.5

Total 50.0 parts Preparation:

The benzodiazepine-dione compound, the lactose and the corn starch are intimately admixed with each other, the mixture is moistened with an aqueous 10 "/1 solution of the gelatin, and the moist mass is forced through a 1 mm-mesh screen. The resulting granulate is dried at 40C and again passed through the screen, the dry granulate is admixed with the magnesium stearate, and the composition is compressed into 50 mgm pill cores which are subsequently coated with a thin shell consisting essentially of a mixture of sugar, titanium dioxide, talcum and gum arabic and finally polished with beeswax. Each coated pill contains 5 mgm of the benzodiazepine-dione compound and is an oral dosage unit composition with effective tranquilizing and anticonvulsive action.

EXAMPLE 17 Suppositories The suppository composition is compounded from the following ingredients:

8-Chloro-1-(o-chlorophenyl)-3H-1,4- bcnzodiazepine-2.5-(1H.4H)-dionc Suppository base (c.g. cocoa butter) 50 parts 1695.0

Total 1700.0 parts EXAMPLE 18 Tablets The tablet composition is compounded from the following ingredients:

bcnzodiazcpine2,5-(1H.4H)-dione 3 parts Lactose 50 Corn starch 32 Soluble starch 4 Magnesium stcaratc 1 Total parts Preparation:

The benzodiazepinc-dionc compound is admixed with the magnesium stcarate. the mixture is granulated with an aqueous solution of the soluble starch. the granulate is dried and intimately admixed with the lactose and the corn starch, and the resulting composition is compressed into 90 mgm-tablets in a conventional tablet making machine. Each tablet contains 3 mgm of the benzodiazepine-dione compound and is an oral dosage unit composition with effective tranquilizing and anticonvulsive action.

Analogous results are obtained when any one of the other benzodiazepine-diones embraced by formula I is substituted for the. particular benzodiazepine-dione in Examples 16 through 18. Likewise, the amount of active ingredient in these illustrative examples may be varied to achieve the dosage unit range set forth above, and the amounts and nature of the inert pharmaceutical carrier ingredients may be varied to meet particular requirements.

While the present invention has been illustrated with the aid of certain specific embodiments thereof, it will be readily apparent to others skilled in the art that the invention is not limited to these particular embodiments, and that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

We claim:

l. A compound of the formula 0 H l. no 2 l, 

1. A COMPOUND OF THE FORMULA
 2. The compound of claim 1 which is 1-phenyl-8-trifluoromethyl-3H-1,4-benzodiazephine-2,5-(1H,4H)-dione.
 3. The compound of claim 1 which is 8-chloro-1-phenyl-3H-1,4-benzodiazepine-2,5-(1H,4H)-dione.
 4. The compound of claim 1 which is 8-chloro-1-(o-chloro-phenyl)-3H-1,4-benzodiazepine-2,5-(1H,4H)-dione.
 5. The compound of claim 1 which is 8-chloro-1-(o-fluoro-phenyl)-3H-1,4-benzodiazepine-2,5-(1H,4H)-dione. 